Re: [RFC][PATCH 1/10] PM: Add flag for devices capable of generating run-time wake-up events

Alan Stern
2009-11-16T21:31:16Z

On Mon, 16 Nov 2009, Matthew Garrett wrote:

> On Mon, Nov 16, 2009 at 04:00:49PM -0500, Alan Stern wrote:
> > On Mon, 16 Nov 2009, Rafael J. Wysocki wrote:
> > > Yes, in general. The platform.
> >
> > And for non-platform devices (hot-pluggable, for example)? Presumably
> > you would want the driver that detects and registers the device to set
> > this flag.
>
> Are there any cases where the bus code won't know this?

None that I'm aware of. I merely wanted to clarify where the flag was
supposed to get set.

> > > > What if the kernel can't tell whether or not the device can generate
> > > > runtime wake-up events?
> > >
> > > Do you have any specific examples in mind?
> >
> > What about Matthew's example of an ACPI GPE which might or might not
> > cause a runtime wake-up event, depending on the AML code in the BIOS?
>
> The platform knows whether or not that's the case.

Okay, then it isn't a problem. Except perhaps in the case of buggy
devices which _should_ generate these events but don't.

Alan Stern